Using colored straws that have been cut into various lengths, let students explore the three types of triangles named by their sides--isosceles, equilateral and scalene.
You will need 4 colors of straws. Cut 14 of one color into 6 mm lengths. Cut 15 of another color into 8 mm lengths. Cut 15 of a third color into 10 mm lengths. Cut 13 of a fourth color into 12 mm lengths.
I put sets in bags and have the students work in groups. When they have discovered the different triangles, they tape them to chart paper and display.